waterproofing need to be done through the above floor not your ceiling and keep inmind it involved hacking, and if your contractor make thing worst, than your will be respondsiable on that. Also since your above is water tank which meant supply to whole building, you didn't want to take risk on it.

Hence I suggest you better get management resolve and you no need to pay a single cents and any risk....


This post has been edited by Jo_da48: Jun 20 2011, 10:19 PM